Error Opening database connection (-50) (4318863)

While clicking on Maintenance | General | Generic Application test connection, the following error is raised even though valid db server name, port number and service name are entered:

Error opening database connection (-50) PS Database: XXXXXX, SQLCODE=-1, SQLDBCode=12541, SQLNrows=0, SQLErrTxt: Ora-1541 (TNS No Listener)

RESOLUTION:

1. Go to Maintenance | General | Generic application connect

2. Be sure to fill out the Database Server column with the Alias for the Database in question. DO NOT put anything in the Database Name column.  It is not being recognized or utilized.